Hang weights from a wire that runs the length of the benches. Add 1/2 kg masses to the copper wire and show that the Stretched deflection goes back when the mass is removed. Use either laser and mirror optical lever to display the deflection or a arrow on the pulley. Add a lot of mass to show the Elastic Limit.

1R20.18

Poisson's Ratio

A rubber hose is stretched to show lateral contraction with increasing length.

1R20.20

Bending or Sagging Board

Ten lbs. is hung from the center of a meter stick supported at the ends. Orient the meter stick on edge and then on the flat. Place the ends of a thin board on blocks, then add mass to the center.

1R20.20

Beams Under Stress

A rectangular cross section bar is loaded in the middle while resting on narrow and broad faces. Hang weights at the ends of extended beams. Use beams of different lengths and cross sections. Hang weights at the ends of extended beams. Use beams of different lengths and cross sections.

1R20.27

Aluminum/Steel Elasticity Paradox

Copper and brass rods sag different amounts under their own weight but steel and aluminum do not.

1R20.31

Stretch a Hole

Holes arranged circle in a rubber sheet deform into an ellipse when stretched.

1R20.32

Deformation Under Stress

A pattern is painted on a sheet of rubber and deformed by pulling on opposite sides.

1R20.38

Stress on a Brass Ring

A strain gauge bridge is used to measure the forces required to deform a brass ring. Diagram. Construction details.

1R20.60

Bologna Bottle

Pound a nail with a Bologna bottle, then add a carborundum crystal to shatter the bottle.

1R20.70

Prince Rupert's Drops

Drops of glass cooled quickly can be hit with a hammer but shatter when the tip is broken off.

1R30. Transfer of Angular Momentum

Use a tall stack of cards placed sequentially off-center to create a ledge.

1R30.20

Materiel Shearing

Push on the top of a large foam block or use a large sponge or use a rectangular block of rubber to show shear of different materials.

1R30.30

Spring Cube

A 3x3x3 cube of 27 cork balls is held together with springs.

1R30.31

Plywood Sheets

A stack of plywood sheets with springs at the corners is used to show shear, torsion, bending, etc.

1R30.35

Shear and Stress Modulus

Unsophisticated apparatus for measuring elastic constants of a thin flexible strip and rod.

1R30.40

Torsion Rod

Rods of various materials and diameters are twisted in a torsion lathe.

1R30.41

Bending and Twisting

Wind a copper strip around a rod and then remove the rod and pull the strip straight to show twisting.

1R30.45

Shear and Twist in Screw Dislocation

Rule a thick walled vacuum tube with a grid, slit lengthwise, and dislocate one unit.

1R30.xx

Train on a Bicycle Wheel

An "O"- Scale train is placed on a horizontal bicycle wheel that is free to rotate. When the train is running, one can let the train go around the track or have it stand still will the track is rotating underneath.

1R30.xx

Wheel and Axle I

A large mid-evil looking wheel on an axle. A large lead ball on a rope is wound up on the axle and the wheel free to rotate.

1R40. Coefficient of Restitution

Drop balls of different material on to a tool steel plate. Loss of mechanical energy in the coefficient of restitution. Drop balls on a glass plate. Balls of various materials are bounced off plates of various materials.

1R40.12

Coefficient of Restitution

Rubber balls of differing elasticity and silly putty are dropped in a clear tube near a meter stick onto a steel surface.

1R40.13

Coefficient of Restitution in Baseballs

Analysis leading to a prediction of up to 15 foot difference in long fly balls due to variation in coefficient of restitution.